# -*- coding: utf-8 -*-

import pygame
from pygame.sprite import Sprite
	
class Ship(Sprite):
	"""docstring for Ship"""
	def __init__(self, ai_setting,screen):
		super(Ship,self).__init__()

		self.screen = screen
		self.ai_setting = ai_setting

		#加载飞船图像并获取其外接矩形
		self.image = pygame.image.load('/Users/lvfeijun/Documents/python/alien/images/ship.bmp')
		self.rect = self.image.get_rect()
		self.screen_rect = screen.get_rect()

		#将每艘新飞船放在屏幕底部最中央
		self.rect.centerx = self.screen_rect.centerx
		self.rect.bottom = self.screen_rect.bottom

		#在飞船中的属性center中存储小数值
		self.center = float(self.rect.centerx)

		#移动标准
		self.moving_right = False
		self.moving_left = False

	def center_ship(self):
		self.center = self.screen_rect.centerx


#根据移动标示调整飞船位置
	def update(self):
		
		if self.moving_right and self.rect.right<self.screen_rect.right:
				self.rect.centerx += self.ai_setting.ship_speed_factor

		elif self.moving_left and self.rect.left>0:
				self.rect.centerx -= self.ai_setting.ship_speed_factor

		#根据self.center 更新rect对象
		#self.rect.centerx = self.center

#在指定位置绘制飞船
	def blitme(self):
		self.screen.blit(self.image, self.rect)
